EDF Economy 7 Calculator
Estimate domestic bills using EDF Economy 7 day and night rates. Compare dual-rate energy usage with standard UK electricity tariffs to maximize savings.
EDF Economy 7 Calculator
💡 Technical Note: EDF Economy 7 provides cheaper electricity during off-peak hours, typically overnight, and actual tariff rates vary by region and meter type.
How to Use EDF Economy 7 Calculator
Estimating your dual-rate energy usage and comparing it with standard domestic tariffs is simple. Follow these step-by-step instructions to calculate your costs using the EDF tariff calculator:
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1Enter day electricity consumption. Input your total daytime energy consumption in kilowatt-hours (kWh) for the chosen billing period.
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2Enter night electricity consumption. Input your off-peak overnight energy consumption in kilowatt-hours (kWh) for the same period.
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3Input EDF tariff rates. Type in the daytime and overnight rates in pence per kWh (p/kWh) specified by your EDF Energy dual rate meter.
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4Enter standing charge. Input the daily standing charge in pence per day (p/day), which is the fixed cost to remain connected to the electricity grid.
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5Select billing period. Select whether your entered consumption represents daily, weekly, monthly, or annual electricity consumption.
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6Click calculate. Click the Calculate button to view the cost breakdown, standing charges, average unit costs, and annual projections.
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7Review cost breakdown. Analyze your total costs and compare them against an optional standard tariff to evaluate your Economy 7 savings.
How to Calculate EDF Economy 7 Costs
To calculate EDF Economy 7 costs, you must separate your daytime peak electricity usage from your off-peak night rate electricity usage, apply the respective rates, and add the fixed daily standing charge. The following equations show how domestic electricity costs are calculated for dual-rate billing systems:
Economy 7 Cost Formulas
Day Cost (£):
Night Cost (£):
Standing Charge Cost (£):
Total Cost (£):
Step-by-Step UK Billing Example
Consider a typical UK household on a dual-rate meter with the following values:
- Day Usage: 250 kWh
- Night Usage: 180 kWh
- Day Rate: 31 p/kWh
- Night Rate: 12 p/kWh
- Standing Charge: 55 p/day
- Billing Period: 30 Days
Step 1 — Calculate Day Electricity Cost
Multiply daytime peak electricity usage by the peak day rate electricity, then divide by 100:
Day Cost = (250 kWh × 31 p/kWh) / 100 = 7,750p / 100 = £77.50
Step 2 — Calculate Night Electricity Cost
Multiply overnight off-peak electricity usage by the night rate electricity, then divide by 100:
Night Cost = (180 kWh × 12 p/kWh) / 100 = 2,160p / 100 = £21.60
Step 3 — Calculate Standing Charge Cost
Multiply the daily standing charge rate by the number of days in the billing cycle, then divide by 100:
Standing Charge Cost = (55 p/day × 30 days) / 100 = 1,650p / 100 = £16.50
Step 4 — Calculate Total Period Cost
Sum the energy costs and standing charge costs together:
Total Cost = £77.50 + £21.60 + £16.50 = £115.60
Step 5 — Calculate Average Unit Cost
Divide the total cost by the total energy consumed to determine the average unit price:
Total Usage = 250 kWh + 180 kWh = 430 kWh
Average Unit Cost = (£115.60 / 430 kWh) × 100 = 26.88 p/kWh
Step 6 — Scale to Annual Cost
Project the monthly total cost to a standard 365-day annual billing period:
Annual Cost = (£115.60 / 30) × 365 = £1,406.47
Walkthrough Final Verified Results
- Day Electricity Cost: £77.50
- Night Electricity Cost: £21.60
- Standing Charge Cost: £16.50
- Total Period Cost: £115.60
- Average Unit Cost: 26.88 p/kWh
- Estimated Annual Cost: £1,406.47
EDF Economy 7 Calculator Chart
The table below outlines the estimated annual costs and potential Economy 7 savings across different monthly energy usage profiles in the United Kingdom. These calculations compare a standard tariff of 24.5 p/kWh with an EDF Economy 7 tariff (31.0 p/kWh day, 12.0 p/kWh night) at 55.0 p/day standing charge.
| Monthly Usage (kWh) | Night Usage % | Estimated Annual Cost (£) | Potential Savings (£) |
|---|---|---|---|
| 200 kWh | 20% | £853.55 | -£64.80 |
| 200 kWh | 40% | £762.35 | £26.40 |
| 400 kWh | 20% | £1,506.35 | -£129.60 |
| 400 kWh | 40% | £1,323.95 | £52.80 |
| 600 kWh | 20% | £2,159.15 | -£194.40 |
| 600 kWh | 40% | £1,885.55 | £79.20 |
| 800 kWh | 20% | £2,811.95 | -£259.20 |
| 800 kWh | 40% | £2,447.15 | £105.60 |
Note: All results in the chart are illustrative. Actual EDF Energy tariffs vary significantly by geographic region and specific smart meter setup.
EDF Economy 7 Calculator Frequently Asked Questions
EDF Economy 7 is a dual-rate domestic electricity tariff offered by EDF Energy in the United Kingdom. It provides two different rates for electricity: a lower off-peak price for seven hours at night, and a higher peak price for daytime usage. This tariff requires a compatible dual-rate meter or a smart meter set up to record night and day usage separately.
Off-peak hours for EDF Economy 7 typically run for a continuous seven-hour window between 11:00 PM and 8:00 AM, commonly 12:00 AM to 7:00 AM or 1:00 AM to 8:00 AM. The exact times are set by the local electricity network and depend on your location, meter configuration, and whether British Summer Time (BST) is active.
An Economy 7 tariff is only cheaper if you consume a substantial portion of your electricity overnight. Since the day rate is higher than a standard single-rate tariff, Ofgem data indicates that households typically need to use at least 30% to 40% of their total energy during the off-peak hours to see a reduction in their overall electricity bills.
Savings depend on your ability to shift high-load appliance usage to the night rate. For households using storage heaters or charging an electric vehicle during off-peak hours, annual savings can exceed £100 to £200 compared to a standard tariff. However, if overnight usage is low, you may end up paying more due to high daytime rates.
No, it does not strictly require a smart meter. Classic mechanical dual-rate meters (such as teleswitches or Radio Teleswitch meters) have been used for decades. However, energy suppliers like EDF Energy are actively replacing older meters with modern smart meters, which automatically switch registers between day and night tariffs.
Yes, homes with electric night storage heaters and hot water cylinders benefit significantly. These systems are designed to draw electricity overnight to heat up fireclay bricks or water at the cheaper night rate, releasing that heat during the day without consuming expensive peak-rate daytime electricity.
To calculate Economy 7 costs, multiply your day consumption by the daytime rate and your night consumption by the night rate. Sum these values, then add the daily standing charge multiplied by the billing days. Divide the total by 100 to convert from pence to pounds. You can use our EDF tariff calculator for quick results.
No, EDF Energy rates vary across the 14 electricity distribution regions in the UK. Regional network transmission charges, local distribution costs, and Ofgem price cap limits cause variations in both standing charges and unit rates. Check your latest energy statement for regional rates.